Coating apparatus



Jam 59 M32. H T. HUNTER 1,840,289

COTING APPARATUS Filed Nov. 16, 1928 2 Sheets-Sheet 2 I//ITIJESSES I N V EN TOR:

A TTORNEYS.

Patented Jan. 5, 1932 UNITED STATES PATENT OFFICE HERBERT T. HUNTER, OF CATONSVILLE, MARYLAND, `.ASSIGNOB' TO DOUGHNUT MACHINE CORPORATION, F NEW YORK, N. Y., A CORPORATION 0I' NEW YORK COATING APPARATUS Application iiled November 16, 1928. Serial No. 319,783.

This invention relates to apparatus for coating articles with pulverulent or granular materials, and while applicable to many other uses, is more particularly concerned with coating of cakes, crullers and doughnuts with i dry sugar.

My invention has for its objects to eii'ect uniform coating of articles of the kind mentioned in a rapid and continuous manner 0 Without danger of injury to them or attendant waste of the coating material; and to provide a simple, eiiiciet, reliable and inexpensive apparatus for the purpose.

One Way in which the foregoing desiderata .5 may be conveniently secured in practice will be manifest from the following detailed description of the typical embodiment of my invention shown in the accompanying drawings, whereof Fig. I is a side elevation of B0 the coating apparatus, the upper portion being broken away and shown in axial section so as to disclose certain important details.

Fig. II is an elevation of the receiving end of the apparatus; and,

25 Fig. III is a similar view of the discharge end of the apparatus.

As herein shown, the apparatus comprises a horizontally rotating drum comprehensively. designated by the numeral 5. This drum 5 embodies two counter-coned shells 6, 7

which are arranged co-axially one within the other with revision of a circumferential interspace 8 etween them. At the receiving end of the apparatus, (that end at the left of Fig. I), the shells 6 and 7 arevsecured to concentric lateral flanges 9, 10 of a head 11, which has a central opening at 12 through which the articles to be coated are introduced into the drum 5 from an inclined gravity chute 13 having a neck 14 projecting into said opening. At the o posite or discharge end of the apparatus, t e shells 6, 7 merge together and are secured to an annulus 15,

which is closed in by a stationary circumferentially-langed head 160i sheet metal having a semi-circular opening 17, near the bottom, that communicates into a discharge chute 18.

The inner shell 6, it will be noted, is con- 50 structed from reticulate material like wire 'ratus b mesh, and, by virtue of its taper, tends to assistgravitationalprogressionof the articles from the smaller end where they are introduced, toward the larger or discharge end. However, to render such'progression positive and thus prevent clogging of the apparatus, the shell 6 is provided, at the interior, with spiral vanes 19 which are comparatively lshallow Vin depth and long-pitched to preclude injury to the articles. The outer shell 7 on the other hand, is imperforate, and ma be conveniently constructed from light s eet metal stock. At the receiving, end of the drum 5, the shell 7 is equipped internally with a series of circumferentlall arranged inwardly-projecting scoops or flights 20 adapted to elevate the coating material in the interspace 8 and release it to drop constantly, through the interstices at the upper side of the inner shell 6, upon the articles concurrently with their introduction into the appathe chute 13. The excess coating release incidental to progression of the artcles in the .drum 5, in turn drops through the bottom of the foraminated inner shell 6 into the interspace 8 to'be conducted rearwardly, as a consequence of gravitational progression induced by the sloping wall of the outer shell 7, for reuse at the receiving end of the apparatus.`

The drum 5 is supported by a sub-structure 24 comprising tranverse end frames 25, 26 which are rigidly connected by lon 'tudinal and diagonal brace members 27, 28, t e whole being secured together by bolts 29. The substructure 24 carries spaced rollers 30, 30 and 31, 31 (Figs. II and III) whereon o ite ends of the drum 5 rest. As shown in igs. I Y and III, the rollers 30, have tapered wedge rooves 32 to engage a complementarily congured circumferential flange 33 ofthe annulus 15, at the correspondin end of the drum 5 with a friction iit. One o the grooved rollers 30 is emplo ed as a driver, and revolves with a ear w eel 34 of a speed reducing train inc uding an intermeshing toothed pinion 35 secured on a shaft 36, with journal bearing in a boss 37 of the frame 26. At its outer end, the shaft 36 carries a sheave 38 which is driven by a belt 39 from an electric motor 100 40, supported on a shelf 41 in the lower part of the sub-structure 24. The rollers 31 have plain faces running in contact with a flat tread 42 surrounding the head 9 at the receiving end of the drum 5. In order to enable positioning of the receiving end of the drum 5 for the urpose of insuring proper tractive coordination between-the grooved rollers 30 and thecircumferential fiange 33 yof the annulus 15, the bearin `members 43 supporting the rollers 31 ares otted, as shown at 44, for adjustment' relative to clamp bolts 45 engaging the end frame 25 of the sub-structure 24. Through the adjustment thus provided, it will be seen that the receiving end of the drum 5 may be shifted vertically to suit the purpose aforesaid.

In operation it will be obvious that through slow constant rotation ofthe drum 5, the coating material (of which a suitable quantity is initiall placed in said drum) will be continuously lifted from the interspace 8 by the vanes 20, and showered from above upon the articles as they enter, by way of the chute 13, into the receiving end of the inner shell A6. With progression induced gently by combined gravitational action of the sloping wall of the screen 6 and therolling action concurrently induced by the spiral blades 19 as the drum 5 rotates, the articles are continuously turned over and over to receive the coatin on all sides and concurrently advance forwardly toward `the discharge outlet 17 and chute 18; the excess coating material incidentally released dropping intothe lower portion of the interspace 8 travelling rearward (by virtue of the counter slope of the outer shell 7) to be again lifted ultimately -by the vanes 20 for discharge upon articles followingin the Wake of the others previously coated.

Through my invention I am thus able to effect coating of doughnuts or the like in a rapid, continuous and sanitary manner, without attendant injury to the articles and without an waste whatever of the coating material. he inherent simplicity of my apparatus is not only conducive to very economic manufacture, but greatl facilitates disassembling of the parts for the purposes of cleanin as required from time to time.

avug thus described my invention, I claim 1. In coating apparatus, a horizontally-rotatin drum comprising two co-axial countershells, one within the other and separated by a circumferential interspace, said inner shell being wholly reticulate and equipped with long-pitched spiral vanes to ensure positive forward gravitational progression o f articles to be coated introduced at the small or. intake end toward the larger or discharge end, the outer shell being imperforate and mer into the inner shell at the delivery om?? the apparatus, and said outer shell serving'to induce rearward gravitation of excess coating material released from the articles incidental to progression through the apparatus into the interspace aforesaid for re-use at the intake end of the drum.

2. In coating apparatus, a horizontally-rotating drum comprising two co-axial counterconed shells, one within the other and separated by a circumferential interspace, said inner shell being wholly reticulate and equipped with internal long-pitched spiral vanes to ensure positive forward gravitational progression of articles to be coated introduced at the small or intake end toward the larger or discharge end, the outer shell being imperforate and merging into t-he inner shell at the delivery end of the apparatus and adapted to induce rearward gravitation of excess coating material released from the articles incidental to the progression throu h the apparatus into the interspace aforesaid for re-use at the intake end of the drum, and circumferentially arranged scoops atthe intake end of the drum to elevate the coating material and release it to drop through the reticulate shell upon the articles at the feed end of the apparatus concurrently with their introduction into said apparatus.

3. In coating apparatus, a horizontally-rotating drum comprising two co-axial countercond shells, one within the other and separated by a circumferential interspace, the inner shell being Wholly reticulate and equipped with internal comparatively shallow long-pitched spiral vanes to ensure positive forward gravitational progression of articles to be coated introduced at the small or intake end toward the larger or discharge end, the outer shell being-imperforate and merging with the inner shell at the outer delivery end of the apparatus and adapted to induce rearward gravitation of excess coating material released from the progressing articles into the interspace aforesaid, and cumferentially-arranged inwardly-projecting scoops in the outer shell at the intake end of the drum to elevate the coating material in the interspace ,and releasing it to drop through the reticulate shell upon the articles at the feed end of the' apparatus concurrently with their introduction into said apparatus.

4. Incoating apparatus, a horizontally-rotating drum adapted to be traversed by the articles being coated, a substructure to support the drum, spaced pairs of rollers whereon opposite ends of the drum rest, one opposing pair Aof said rollers having tapered grooves to engage a complementarily-sectioned circumferential flange at corresponding end of the drum, and means associated with the bearings of the other pair of rollers enabling positional adjustment of the .drum at the other end to insure frictional tractive coordination between the grooved rollers and the circumferential flange aforesaid.

5. In coating apparatus, a horizontally-rotating drum adapted to be traversed by the 5 articles being coated, a supporting substructure with bearings for spaced rollers upon which the drum rests at opposite ends, one set of said rollers having grooves to engage a circumferential flange of the drum with 10 a wedge fit, means enabling adjustment of the bearings for the other set of rollers to position the corresponding end of the drum and thereby determine proper tractive coordination between the grooved rollers and the cir- 15 cumferential ange aforesaid, and means to drive one of the grooved rollers.

In testimony whereof, I have hereunto signed my name at Ellicott City, Md., this 13th day of November 1928.

2o HERBRT T. HUNTER. 

